first commit

exectrace/recorder/fs_tracker.py

@@ -0,0 +1,91 @@
+from __future__ import annotations
+
+import base64
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Dict, List, Tuple
+
+from exectrace.utils.hash_utils import sha256_bytes
+
+
+@dataclass
+class FileSnapshotEntry:
+    sha256: str
+    size: int
+
+
+def snapshot_directory(root_dir: Path) -> Dict[str, FileSnapshotEntry]:
+    """Capture a file snapshot for deterministic change detection."""
+    snapshot: Dict[str, FileSnapshotEntry] = {}
+    for path in root_dir.rglob("*"):
+        if path.is_file() and ".git" not in path.parts:
+            rel = str(path.relative_to(root_dir))
+            content = path.read_bytes()
+            snapshot[rel] = FileSnapshotEntry(sha256=sha256_bytes(content), size=len(content))
+    return snapshot
+
+
+def encode_file_content(path: Path) -> Tuple[str, bool]:
+    content = path.read_bytes()
+    try:
+        content.decode("utf-8")
+        is_binary = False
+    except UnicodeDecodeError:
+        is_binary = True
+    return base64.b64encode(content).decode("ascii"), is_binary
+
+
+def diff_snapshots(
+    root_dir: Path,
+    before: Dict[str, FileSnapshotEntry],
+    after: Dict[str, FileSnapshotEntry],
+) -> List[dict]:
+    actions: List[dict] = []
+
+    before_paths = set(before.keys())
+    after_paths = set(after.keys())
+
+    created = sorted(after_paths - before_paths)
+    deleted = sorted(before_paths - after_paths)
+    possibly_modified = sorted(before_paths & after_paths)
+
+    for rel_path in created:
+        file_path = root_dir / rel_path
+        encoded, is_binary = encode_file_content(file_path)
+        actions.append(
+            {
+                "action_type": "file_create",
+                "payload": {
+                    "path": rel_path,
+                    "content_b64": encoded,
+                    "is_binary": is_binary,
+                },
+            }
+        )
+
+    for rel_path in possibly_modified:
+        if before[rel_path].sha256 != after[rel_path].sha256:
+            file_path = root_dir / rel_path
+            encoded, is_binary = encode_file_content(file_path)
+            actions.append(
+                {
+                    "action_type": "file_modify",
+                    "payload": {
+                        "path": rel_path,
+                        "content_b64": encoded,
+                        "is_binary": is_binary,
+                    },
+                }
+            )
+
+    for rel_path in deleted:
+        actions.append(
+            {
+                "action_type": "file_delete",
+                "payload": {
+                    "path": rel_path,
+                },
+            }
+        )
+
+    return actions